Method and apparatus for casting metal articles



Jan. 5, 1965 E. Q. SYLVESTER 3,163,897

METHOD AND APPARATUS FOR CASTING METAL ARTICLES Filed May 21, 1962 4 Sheets-Sheet 1 INVENTOR.

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METHOD AND APPARATUS FOR CASTING METAL ARTICLES Filed May 21, 1962 Jan. 5, 1965 E. Q. SYLVESTER 4 Sheets-Sheet 3 INVENTOR. v

Edmund wesfw Jan. 5, 1965 E. Q. SYLVESTER 3,163,397

METHOD AND APPARATUS FOR CASTING METAL ARTICLES Filed May 21, 1962 4 Sheets-Sheyet 4 J6L7\ 168 i J58\ D J72 154 166 INVENTOR.

J62 Q) ZQZ7 7 United States Patent grease! Marnon AND arranaros non cns u l n METAL ARTIQLES Edmund Q. Sylvester, Shaker Heights, Ohio Arne-ted industries End, Frutientiai Plaza, Qhicago 1, ill.) Filed May 21, 1962, Ser. No. 1%,2-i

This invention relates generally to the art of casting of metals and more specifically to a method and apparatus for pressure pouring of metal articles.

Various forms of apparatus have been proposed for the pressure pouring of molten metal. One of these, for example, is the provision of a pressurized ladle structure having a generally vertically extending pouring tube externally of and in communication with the metal-conraining chamber of the ladle body. Although such structures are generally satisfactory, some have exhibited a tendency to have the molten metal freeze within the external pouring tube during such periods as when the ladle structure is subjected to adverse conditions.

The very nature of such pressure pouring arrangements makes them particularly suitable to highly repetitive casting operations. Accordingly, the metal-containing chamber of the ladle body is normally of a size sufiicient for the containment of that quantity of molten metal which will fill a plurality of successive mold cavities.

However, during certain periods of operation, as, for I example, the non-availability of mold assemblies, prolonged periods of time between successive molds or any other occasioned delay, molten metal will remain in a rather static state within the pouring tube. When the molten metal is allowed to so remain in the pouring tube for excessive periods of time, freezing of the metal occurs causing possible damage and further costly delays.

Means have been suggested for preventing such undesirable freezing by providing various apparatus for capping the top of the pouring tube and applying a pressurized gas to within the pouring tube so as to force the molten metal out of such tube and generally into the metalconta'ming chamber of the ladle assembly. Although such capping means have been found to be effective in preventing freezing within the pouring tubes, they nevertheless have not been totally accepted in that, in many instances, the time required to both engage and disengage the capping means to the pouring tube, prior to pressure pouring, has been excessive. That, is, because of the nature of the capping means, the intended mold and gate assembly cannot be connected to the pouring tube until after the capping means are first disengaged and removed from the pouring tube.

Accordingly, an object of this invention is to provide a method of pressure pouring metal articles whereby the freezing of molten metal within the pouring tube is prevented.

Another object of this invention is to provide means for at times displacing the molten metal from the pouring tube so as to substantially reduce the rate of cooling of the molten metal.

A still further object of this invention is to provide means for at times displacing the molten metal from the pouring tube in a manner permitting the connection of a mold and gate assembly to said pouring tube without the necessity of first disconnecting said means.

Still other objects and advantages of the invention will become apparent when reference is made to the following written description taken in conjunction with the drawings wherein:

FIGURE 1 is a vertical cross-sectional view of a ladle structure, embodying the invention, in combination with a suitable mold assembly;

FIGURE 2 is an enlarged fragmentary cross-sectional 7 3,163,897 Fatented Jan. 5, 1965 view illustrating in greater detail a portion of the pouring tube assembly shown in FIGURE 1;

FIGURE 3 is a view, similar to that of FIGURE 2, illustrating a second embodiment of the invention;

FEGURE 4 is a perspective View, with a portion thereof broken away, illustrating in greater detail one of the elements comprising the invention as disclosed in FIG- URE 3;

FIGURE 5 is a view, similar to that of FIGURES 2 and 3, illustrating a third embodiment of the invention;

FEGURE 6 is a fragmentary cross-sectional view illustrating an arrangement for passing a-pressure conduit through the Wall defining the chamber containing the ladle assembly;

FIGURE 7 is a fragmentary cross-sectional View taken substantially on the plane of line 7-7 of FIGURE 6 and looking in the direction of the arrows;

FIGURE 8 is a view illustrating one arrangement for connecting a source of superatmospheric fluid pressure to the pouring conduits of either FIGURES 2, 3 or 5; and

FlGURE 9 is an enlarged cross-sectional View of one of the elements shown in FIGURE 8.

Certain details are omitted in the drawings for purposes of clarity.

Referring now in greater detail to the drawings, FIG- URE 1 illustrates a pressure pouring ladle assembly 10 comprised of a ladle body 12 and a pouring tube assembly is, suitably secured thereto, located in a pit 16 defined generally by a Wall member 18.

The ladle body 12 may be comprised of firebrick 2i lining the inner walls of an outer container 22 so as to define a chamber 24 for the reception of molten metal therein. The pouring tube assembly 14, comprised of an outer casing 26 containing clay tile 28 surrounded by sand Ed in a manner defining a conduit 32, may be secured by any suitable means to the container 22 as at 34. The lower portion of chamber 24 is brought into communication with conduit 32 by means of a conduit portion 35 formed generally by the firebrick 20 of the ladle 12.

A cover assembly 38, having a flange 40 secured to a' downwardly depending cylindrical portion 42, is secured in sealing engagement to the Wall member 13 as by means of a seal member 44. Any suitable clamping devices may, of course, be employed for retaining the cover assembly in such engagement. A bellows member 46, sealingly secured at its upper end to the cover assembly 33 also serves to seal the'charnber of pit 16 from the ambient atomsphere by resiliently urging the seal member 5@ into engagement with the radially extending flange 48 formed on the pouring tube 14.

A suitable gate and mold assembly 52 is shown as being connected to'the top of the pouring tube 14.

FIGURE 2 illustrates the upper end 54 of the pouring tube as being formed to provide an annular pouring head 56 suitably secured to a radial flange portion 58 formedon the outer casing 26 The pouring head 56 is provided with an outer conical surface adapted to mate with a generally conical recess 62 formed in the lower portion of the mold and gate assembly 52. If desired, a castable refractory 64 may be placed atop the sand mixture 3t? in a manner forming a ring between the clay tile 28 and pouring head 56.

An aluminum disc 66 is generally peripherally retained to the top of head 56 by means of an annular nut member 63 which is threadably engaged with pouring head 56. Nut 68 may be provided with oppositely disposed notches or slots '76? and '72 in order to enable assembly thereof as by means of a spanner wrench. An annular gasket 74, preferably comprised of asbestos, is provided atop disc 66 so as to experience a calculated range of compression between disc 66 and surface 'idwhen the mold and gate assembly 52 is assembled to the pouring tube 14. A conduit 78 communicating at its one end with a suitable source 89, of fluid pressure has its other end terminating in surface 82 of head 56 against which the disc 66 is retained by nut 63.

, Operation For purposes of illustration, let it be assumed that ladle assembly 18, is, empty and: transported to a suitable station for filling. At this time the top end 54 of the pour.- ing tub would be open to the atmosphere.

After the ladle chamberwas filled to a predetermined level with molten metal, the aluminum disc or cap 66 would be placed atop pouring head 56 and secured thereto by meansof nut 68, thereby sealing the upper end of the pouring tube from the ambient atmosphere. Conduit 78- would then be operatively connected to a source of fluidpressure 80ers by means of suitable conduitry 84 and valving means, 86 which valving means would then be opened so as to allow relatively high pressure gas to flow into conduit 73. Consequently, the alurninum disc 66 is. caused to bow upwardly a slightarnountallowing communication between conduit 78 and pouring conduit 32. The application of such high --pressure gas is continued until such time as when substantially allthe molten metalwith-in the pouring tube is forced into chamber 24 at which time the gas pressure is maintained only to the point to maintain equilibrium.

The filled ladle assembly may then be transported to and lowered into a suitable pit 16 and sealed therein with cover assembly 38. The mold and gate assembly 52 is then connected to the upper end 54 of the pouring tube assembly 1.4 as shown by both FIGURES l and 2. During-the above sequence of operations the pouring tube conduit is preferably continuously maintainediunder pressure thereby keeping substantially all the molten metal outof conduit 32;

When pressure; casting is desired, the previously created pressure within conduit 32; is first relieved thereby allowing-the molten metalwithin chamber 24 to gravitationally flow into conduit 32 until a balance of levels is attained; Next, superatmospheric gas pressure is admitted to pit 16 by means of suitable conduitry 88, valve means 9t and a source of, fluid pressure 92.

As the pressure within chamber 16 increases, a correlative riseof molten metal within conduit 32 occurs thereby bringing the metal level increasingly closer to the alu minum disc 66. The heat of the molten metal then causes the aluminum disc 66 to melt thereby creating an orifice therethrough, ofa size closely approximating that of the pouring conduit 32, so as to complete communication between conduit; 32 and, the inlet conduit 94 of the mold and gate assembly 52'. Source 92 continues to supply superatmospheric pressure'until the mold cavity is filled at which time application of such pressure is ter- Ininatedv and another gate and'mold assembly connected to the pouring tube assembly. Successive mold assemblies are thusly connected, filled and'rernovcd until all or substantially all of the molten metal within chamber 24 is exhausted.

FIGURE 3 is a modification of the invention and all elements which are like or similar to those of FIGURES 1 and 2 are identified with like reference numbers. In the embodiment of FIGURE 3, a pouring head 96 is provided with an annular groove 98 formed generally. in the conical surface 100. An aluminum cap or cover 192,

having a conical portion 184, and pouring head as. co-

operate in retaining a heat resistant gasket 106 therebetwcen. Cover 102 is also provided with an inwardly directed radially extending flange portion 168, which may be formed at time of assembly to the pouring head 96, and a generally downwardly depending hook portion 11%, of annular cross-section, adapted to be engaged by a preferably resilient annular seal 112 A metallic retaining strap 114 may also be provided to urge the seal 112 and hook portion 110 inwardly towards the inner surface 116 of the groove 98.

When superatmospheric pressure is applied through conduit 78 the gasket 1% is urged upwardly allowing the pressure to flow into conduit 32 in the same manner as previously described in connection with FIGURE 2. Any possible leakage of pressure between the conical surface 1th and portion 194 will, of course, be prevented from communication with the ambient atmosphere by virtue of seal 112.

FIGURE 4 illustrates, by way of example, one form which the cover 102 may assume prior to assembly to. pouring head 96. Cover 102v is shown with a fragmem tar y portion thereof broken away in order to better illusirate the relationship between the various portions com-. prising the cover. That is, portion 104. is preferably formed so as to closely approximate the slope and size; of the conical surface 109 while portion 108 is formed to. allow the upper outer diameter 1180f groove 98.to.freely pass thcrethrough. A plurality of slots 129, of which two are shown, may be formed through both'portions 108 and 119 in order to facilitate athering of the material. as portion 1% is bent under. groove 93 as illustrated in FIGURE 3 upon assembly tothe pouring head 96.

In the embodiment of FIGURE 5, wherein all. ele

ments which are like or similar to those of FIGURES 1, 2 or 3 are identifiedv with like reference numbers, an aluminum cover or cap 122 is retained between an. an nular clamping plate 124 and the top of the pouring head- 126 by means of a plurality of screws 128, of whichonly two are shown, threadably engaging the head 12 6. A groove 13% may be formed within the gate assembly 52- in order to accommodate any extensions of screws 128. The mode of operation of the embodiment of FIGURE 5 isthe same as that disclosed in connection with FIGURES- 1 and 2. Whenever the ladle assembly is lowered into a pit and closed as by cover assembly 38, the conduitry 84 as schematically illustrated in FIGURE 2 may be temporarily disconnected fromconduit 78 in order topermit closure of the cover assembly 38. However, FIGURES 6-9 illustrate arrangements permitting continuous communication between the source of high pressure and pouring conduit 32 even during the time in which the cover 42 is being assembled to the wall structure 18.

For example, FIGURES 6 and. 7 illustrate the wall member 18 and cover assembly 38- as being formed to provide arcuate portions 132 and 134 so as to receive conduit 84 therebetween. A reinforcing ring member 136 sealingly secured to conduit 84 provides an abutting surface for a resilient annular seal 138 as it is compressed radially inwardly by portions 132 and 134 of cover assembly 38 and wall member 18, respectively.

Conduit 84 may also be provided with a flange 140 which, after assembly, abuts against the inner surfaces of arcuate portions 132 and 134thereby. preventing accidental withdrawal of conduit. 84 and seal 138.

The arrangement illustrated by FIGURES 6 and 7 enables the capped ladle assembly to be lowered into pit 16 and the cover assembly 38 secured to wall member 18 without having to in any way disengage conduit 84 from either conduit 78- or source 80.

FIGURE 8 illustratesanother arrangement for enabling continuous communication between conduit 32 and pressure source 80 during such periods as when, the cover assembly 38 is being lowered onto Wall member 18 and about pouring tube assembly 14. A conduit. 142, operatively connected to pressure source 80, is provided with branch conduits 144 and 146 containing flow control valve assemblies 148 and 150,'respective1y. Conduits 144- and 146, each equipped with coupling members 152, are intended to be selectively connected to an inlet assembly 154 at the lower end of the extension of conduit 78.

Inlet assembly 154, as shown by FIGURE 9, is comprised of a body 156 containing a conduit 158 formed therethrough and provided with seating surfaces 160 and 162 which cooperate with ball valve members 164 and 166, respectively; Biasing springs 168 and 170 may be provided in order to assure seating of valve members 164 and 166. Conduit 172 completes communication between conduits 158 and 78. Externally threaded projections 174 and 176 are provided for connection to couplers 152 of conduits 144 and 146.

With the arrangement of FIGURE 8, the normal sequence of operations appertaining the assembling of the cover 38 to the wall 18, would be as follows.

After cap 162 was secured to the pouring tube 14, conduit 146 would be connected to inlet assembly 154, as by means of threaded portion 176, and valve 150 opened thereby allowing the high pressure gas of source 89 to unseat valve member 166 and pressurize pouring conduit 32. During this time, conduit 144 would be disconnected and valve 148 maintained closed.

Ladle assembly 16 with conduit 146 connected thereto may then be lowered into pit 16, as shown in FIGURE 1, and cover assembly 33 brought into position for the reception of pouring tube 14 therethrough. At this time, conduit portion 144 may be brought over the top of cover 38 and connected to threaded portion 174 of the inlet assembly 154 and valve 148 opened. Valve 159 is then closed, conduit 146 disconnected from inlet 154 and the cover assembly lowered onto and secured to wall member 18. Valve members 164 and 166, of course, act as check valves thereby preventing reverse flow therethrough whenever either conduit 144 or 146 is disconnected from inlet 154. A valve 178, serially connected with conduit 78, is provided for at times venting conduit 78 and pouring conduit 32 to the atmosphere. A valve such as 178 or the functional equivalent thereof may be provided for each of the embodiments of FIGURES 2, 3 and 5 in order to relieve the pressure within pouring conduit 32 prior to the pressure pouring cycle.

The invention, as disclosed, has many important advantages. For example, the employment of any of the pouring tube caps or covers as disclosed enables the pouring conduit 32 to be maintained in a continued pressurized state, thereby displacing the molten metal therein, until almost the very instant that pressure pouring of molten metal is initiated. This, of course, is brought prior thereto.

Although aluminum has been disclosed as being the preferred metal from which the various pouring tube covers are made, other metals are also suitable for the practice of the invention. For example, the cover could be made of a metal having the same composition as that which is contained within the ladle chamber 24. The primary considerations, of course, are that the cover be made thin enough so as to be capable of at least slightly bowing under pressure and melting when exposed to a heat level which the molten metal 62 is capable of supplying.

Although but three basic embodiments of the invention have been disclosed and described, it is, of course, apparent that other modifications are possible within the scope of the appended claims.

I claim:

1. A method of pressure casting metal articles from a ladle structure having an upwardly extending pouring tube, comprising filling the ladle structure with molten metal to a predetermined level, securing suitable sealing means to the upper end of the pouring tube in order to seal said pouring tube from the atmosphere, pressurizing the pouring tube with supereatmospheric pressure until the molten metal within the pouring tube has been sub stant-ially removed therefrom, maintaining said pouring tube in such a pressurized state until a mold assembly is made ready to be placed into pouring engagement with said pouring tube, reducing the pressure within the pouring tube until it reaches substantially atmospheric pressure, and applying superatmospheric pressure to said ladle structure in order to force the molten metal out of said ladle structure upwardly through said pouring tube and disintegrate said sealing means and flowtherethrough so as to fill said mold assembly.

2. A method of pressure casting metal articles from a ladle structure having an upwardly extending pouring tube, comprising filling the ladle structure with molten metal to a predetermined level, securing suitable fusible sealing means to the upper end of the pouring tube in order to seal said pouring tube from the atmosphere, pressurizing the pouring tube with superatmospheric pressure so as to force molten metal from the pouring tube and into the ladle structure, maintaining said pouring tube in such a pressurized state until a mold assembly is made ready to be placed into pouring engagement with said pouring tube, reducing the superatmospheric pres-- sure within the pouring tube and applying superatmos pheric pressure to said ladle structure in order to force the molten metal out of said ladle structure upwardly through said pouring tube and fuse said sealing means and flow therethrough so as to fill said mold assembly.

3. In an arrangement for pressure casting metal articles, a ladle assembly comprising a ladle body, a chamber formed within said ladle body containing molten metal therein, a pouring tube assembly formed externally of said ladle body having an upwardly directed open end and a lower end communicating with a lower portion of said chamber, a sealing member secured atop said open upper end sealing the interior of said pouring tube assembly from the atmosphere, said sealing member being relatively thin and readily fusible by the molten metal, first conduit means communicating between the interior of said pouring tub-e assembly and a source of superatmospher-ic pressure for at times directing superatmospheric pressure to the interior of said pouring tube assembly, an outer container for receiving said ladle body and pouring tube assembly, a cover member adapted to receive therethrough said upper end of said pouring tube and adapted to be secured in sealing engagement with both said outer container and said pouring tube, a mold assembly functionally engaging said upper end of said pouring tube assembly, and second conduit means communicating with said source of superatmospheric pressure for at times forcing said molten metal out ofsaid chamber upwardly through the pouring tube assembly and said sealing member into said mold assembly.

4. In an arrangement for pressure casting metal articles, a ladle assembly comprising a ladle body, a chamber formed Within said ladle body containing molten metal therein, a pouring tube assembly having a passage therein and having an upwardly directed open end and a lower end communicating with a lower portion of said chamber, a fusible sealing member secured atop said open upper end sealing the interior of said pouring tube assembly from the atmosphere, said sealing member having a limited degree of flexibility and engaging the marginal portion of the pouring tube around the passage therein, first conduit means extending through said marginal portion of the pouring tube and thereby communicating with the interior. of said pouring tube assembly, also communicating with a source of superatmospheric pressure, the superatmospheric pressure being effective for flexing said sealing member whereby to enable pressure to be directed under the sea-ling member and into the interior of said pouring tube assembly, a mold assembly functionally engaging with said upper end of said pouring tube assembly, and second conduit means communicating with said source of superatrnospheric pressure for at times directing said superatmospheric pressure to said molten metal within said chamber so as to force said molten metal out of said chamber upwardly through the pouring tube assembly and said first sealing member into said mold assembly.

'5. Apparatus for casting metal, comprising a refractory-lined ladle containing molten metal and having an outlet opening formed in the lower portion thereof, a separate generally upright s'pout struoturedefining a refraotor'y-lined pouring conduit having an upper outlet end and a lower inlet end in communication with said outlet opening, first sealing means for sealing said ladle from the ambient atmosphere, second sealing means of relatively low fusion point for sealing said upper outlet end, a mold assembly suitably connected to said upper outlet end, means for at times admitting a first superatmospheric pressure fluid to said pouring conduit sufficient to cause displacement of said molten metal therein, and additional means for subsequently admitting a second superatmospheric pressure fluid against said molten metal Within said ladle in order to cause said molten metal to flow out of said ladle through said conduit and fuse said second sealing means and flow therethrough into said mold assembly.

6. Apparatus for casting metal, comprising a refractory-lined ladlescontaining molten metal and having an outlet opening formed in the lower portion thereof, a separate generally upright spout structure defining a refractory-lined pouring conduit having an upper outlet end and a lower inlet end in communication with said outlet opening, a relatively thin flexible aluminum disc sealing said upper outlet end, a mold assembly suitably connected to said upper outlet end, means for at times admitting a first superatmospheric fluid pressure to said pouring conduit sufiicient to depress the level of said molten metal therein, including conduit means opening in said spout structure under said disc, the disc being readily flexed by superatmospher-ic pressure whereby to enable the latter to flow into the pouring conduit, means for venting said first superatmospheric fluid pressure to the atmosphere, and additional means for subsequently admitting a second superatrnosphe'ric fluid pressure against said molten metal within said ladle in order to cause said molten metal to flow out of said ladle through said conduit and fuse said sealing means and flow therethrough into said mold assembly.

7. A method of pressure pouring cast metal articles with a ladle having an open top and an upwardly extending pouring tube in communication atits lower end with an orifice formed in a lower portion of said ladle comprising rthe steps of filling the ladle with molten metal, securing flexible sealing means to the uppermost end of said upwardly extending pouring tube, creating a first superatmospheric pressure within said pouring tube by tnansmitting it through a conduit, sufficient to substantially depress the level of the molten metal within said pouring tube, utilizing said sealing means for closing said conduit against flow of molten metal thereinto, transporting said filled ladle to a pit and lowering said ladle into said pit so that the uppermost end of said pouring tube projectsa distance thereabove, sealing said pit from the ambient atmosphere, placing a suitable mold structure into functional engagement with said uppermost end of said pouring tube, reducing said first superatmospheric pressure within said pouring tube, and applying a second superatmospheric pressure to said sealed pit to cause said molten metal within said ladle to flow outwardly through said orifice upwardly through said pouring tube and fuse said sealing means and flow therethrough into said mold structure.

8. In an arrangement for pressure casting metal articles, a ladle assembly comprising a ladle body, a chamber formed within said ladle body containing molten metal therein, a pouring tube assembly formed externally of said ladle body having an upwardly directed open discharge end and a lower inlet end in free communication with a lower portion f said chamber, a sealing arrangemerit for sealing said upper discharge end from the atmosphere, said sealingarrangement comprising a thin metallic disc having one side in abutting relationship to the top of said upper discharge end and positioned so as to be in general axial alignment with said pouring tube, an externally threaded portion formed about the upper discharge end of said pouring tube, an annular retaining nut internally threaded so as to engage said externally threaded portion, an inwardly directed annular flange portion formed on said nut and adapted to engage all annu lar portion of the uppermost side of said disc so as to clamp said disc to the top of said upper discharge end as said nut is brought into complete engagement with said externally threaded portion, first conduit means communieating between the interior of said pouring tube assembly and a source of superatmospheric pressure for at times directing superatmospheric pressure to the interior of said pouring tube assembly, a mold assembly functionally engaging said upper discharge end in a manner retaining a generally annular resilient gasket between said mold assembly and said disc, and second conduit means communicating with said source of superatmospheric pressure for at times directing said superatniospheric pressure to said molten metal within said chamber so as to force said molten metal out of said chamber upwardly through the pouring tube assembly and said metallic disc into said mold assembly. I

9. In an arrangement for pressure casting metal articles, a ladle assembly comprising a ladle body, a chamber formed within said ladle body containingmolten metal therein, a pouring tube assembly formed externally of said ladle body. having an upwardly directed open discharge end and a lower inlet end in free communication with a lower portion of said chamber, a sealing arrangement for sealing said upper discharge end from the atmosphere, said sealihg arrangement comprising a thin metallic disc having one side in abutting relationship to the top of said upper discharge end and positioned so as to be in general axial alignment with said pouring tube, an anhular retaining ring placed atop said disc in relatively close proximity to the periphery of said disc, a plurality or clearance holes formed in said ring and spaced generally circumferentially thereab'out, a plurality of tapped holes formed in said upper discharge end in axial alignment with said clearance holes, a plurality of screws received through said clearance holes th're'ad'a'bly engagsembly, a mold assembly functionally engaging said upper discharge end in a manner retaining a generally annular resilient gasket between said mold assembly and said disc, and second conduit means communicating with said source of superatmospheric pressure for at times directing said superatmospheric pressure to said molten metalwithin' said chamber so as to force said molten metal out of said chamber upwardly through the pouring tube assembly and said metallic disc into said mold assembly.

10. In an arrangement for pressure casting metal articles, a ladle assembly comprising a ladle body, a chamber formed within said ladle body containing molten metal therein, a pouring tube assembly formed externally of said ladle body having an upwardly directed open discharge end and a lower inlet end in free communication with a lower portion of said chamber, a sealing arrange- I ment for sealing said'upper discharge end from the atmosphere, said sealing arrangement comprising a thin metallic dish-like member having one side in abutting relationship to the top of said upper discharge end and positioned so as to be in general axial aligment with said pouring tube, an annular groove formed about said pouring tube near the uppermost end thereof, an extending portion formed on said dish-like member adapted to be bent inwardly so as to form a generally inwardly directed radial flange portion received within said annular groove, a generally downwardly depending hook portion formed on said flange portion, a resilient sealing gasket closely received within said annular groove radially outwardly of said hook portion in a manner urging said hook portion radially in- Wardly of said annular groove, retaining means contacting an outer surface of said sealing gasket so as to both urge said gasket radially inwardly of said annular groove and confine said gasket, first conduit means communicating between the interior of said pouring tube assembly and a source of superatmospheric pressure for at times directing superatmospheric pressure to the interior of said pouring tube assembly, a mold assembly functionally engaging said upper discharge end in a manner generally confining said dish-like member between said mold assembly and said upper discharge end, and second conduit means communicating with said source of superatmospheric pressure for at times directing said superatmospheric pressure to said molten metal within said chamber so as to force said molten metal out of said chamber upwardly through the pouring tube assembly and said metallic dish-like member into said mold assembly.

: 11. A method of pressure pouring cast metal articles with a ladle having an open top and an upwardly extending pouring tube in communication at its lower end with an orifice formed in a lower portion of said ladle comprising the steps of filling the ladle with molten metal,

securing relatively easily disintegratable sealing means to the uppermost end of said upwardly extending pouring tube, pneumatically connecting the interior of said pouring tube to a source of superatmospheric pressure fluid by means of a first conduit, creating a first superatmos pherio pressure within said pouring tube suficient to 'sub stantially depress the level of the molten metal Within said pouring tube, utilizing said sealing means for closing said first conduit against flow of molten metal thereinto, transporting said filled ladle to a pit and lowering said ladle into said pit so that the uppermost end of said pouring tube projects a distance thereabove, positioning a cover member over said ladle and first conduit and about said pouring tube, pneumatically connecting the interior of said pouring tube to said source of superatmospheric pressure fluid by means of a second conduit placed above said cover member, disconnecting said first conduit while maintaining said first superatmospheric pressure within said pouring tube with said second conduit, lowering said cover onto andabout said pit so as to seal said pit from the ambient atmosphere, placing a suitable mold structure into functional engagement with said uppermost end of said pouring tube, reducing said first superatmospheric pressure, and applying a second superatmospheric pressure to said 'sealed'pit to cause said molten metal within said ladle to flow outwardly through said orifice, upward- 1y through said pouring tube and disintegrate said sealing means and flow therethrough into said mold structure.

References Cited by the Examiner FOREIGN PATENTS 726,354 3/55 Great Britain.

MICHAEL V. BRINDISI, Primary Examiner.

WILLIAM J. STEPHENSON, Examiner. 

11. A METHOD OF PRESSURE POURING CAST METAL ARTICLES WITH A LADLE HAVING AN OPEN TOP AND AN UPWARDLY EXTENING POURING TUBE IN COMMUNICATION AT ITS LOWER END WITH AN ORIFICE FORMED IN A LOWER PORTIOIN OF SAID LADLE COMPRISING THE STEPS OF FILLING THE LADLE WITH MOLTEN METAL, SECURING RELATIVELY EASILY DISINTEGRATABLE SEALING MEANS TO THE UPPERMOST END OF SAID UPWARDLY EXTENDING POURING TUBE, PNEUMATICALLY CONNECTING THE INTERIOR OF SAID POURING TUBE TO A SOURCE OF SUPERATMOSPHERIC PRESSURE FLUID BY MEANNS OF A FIRST CONDUIT, CREATING A FIRST SUPERATMOSPHERIC PRESSURE WITHIN SAID POURING TUBE SUFFICIENT TO SUBSTANTIALLY DEPRESS THE LEVEL OF THE MOLTEN METAL WITHIN SAID POUURING TUBE, UTILIZING SAID SEALING MEANS FOR CLOSING SAID FIRST CONDUIT AGAINST FLOW OF MOLTEN METAL THEREINTO, TRANSPORTING SAID FILLED LADLE TO A PIT AND LOWERING SAID LADLE INTO SAID PIT SO THAT THE UPPERMOST END OF SAID POURING TUBE PROJECTS A DISTANCE THEREABOVE, POSITIONING A COVER MEMBER OVER SAID LADLE AND FIRST CONDUIT AND ABOUT SAID POURING TUBE, PNEUMATICALLY CONNECTING THE INTERIOR OF SAID POURING TUBE TO SAID SOURCE OF SUPERATMOSPHERIC PRESSURE FLUID BY MEANS OF A SECOND CONDUIT PLACED ABOVE SAID COVER MEMBER, DISCONNECTING SAID FIRST CONDUIT WHILE MAINTAINING SAID FIRST SUPERATMOSPHERIC PRESSURE WITHIN SAID POURING TUBE WITH DAID SECOND CONDUIT, LOWERING SAID COVER ONTO AND ABOUT SAID PIT SO AS TO SEAL SAID PIT FROM THE AMBIENT ATMOSPHERE, PLACING A SUITABLE MOLD STRUCTURE INTO FUNCTIONAL ENGAGEMENT WITH SAID UPPERMOST END OF SAID POURING TUBE, REDUCING SAID FIRST SUPERATMOSPHERIC PRESSURE, AND APPLYING A SECOND SUPERATMOSPHERIC PRESSURE TO SAID SEALED PIT TO CAUSE SAID MOLTEN METAL WITHIN SAID LADLE TO FLOW OUTWARDLY THROUGH SAID ORIFICE, UPWARDLY THROUGH SAID POURING TUBE AND DISINTEGRATE SAID SEALING MEANS AND FLOW THERETHROUGH INTO SAID MOLD STRUCTURE. 